Unit 4 AP Biology Insta-Review (Cell Communication & Cell Cycle)

Front

What is the role of cyclin in the cell cycle?

Back

Cyclin levels increase at specific points in the cell cycle to activate cyclin-dependent kinases (CdKs), which regulate progression through the cycle.

Front

What is a cyclin-dependent kinase (CdK)?

Back

CdKs are enzymes that, when activated by cyclins, phosphorylate target proteins to drive the cell cycle forward.

Front

How do cyclin levels change during the cell cycle?

Back

Cyclin levels increase and decrease at different phases of the cell cycle, peaking at specific points to regulate progression.

Front

What is a competitive inhibitor?

Back

A competitive inhibitor is a substance that binds to the active site of an enzyme, preventing the substrate from binding.

Front

What is a ligand in cell signaling?

Back

A ligand is a signaling molecule that binds to a receptor to initiate a cellular response.

Front

What type of feedback mechanism is involved when ethylene causes more ethylene to be released during fruit ripening?

Back

This is an example of a positive feedback mechanism.

Front

What is the difference between positive and negative feedback in biological systems?

Back

Positive feedback amplifies a response, while negative feedback reduces or inhibits a response.

Front

Do different cells respond to the same signal in the same way?

Back

False. Different cells can respond differently to the same signaling molecule based on their specific receptors and pathways.

Front

What is an allosteric inhibitor?

Back

An allosteric inhibitor is a molecule that binds to an enzyme at a site other than the active site, changing the enzyme's shape and reducing its activity.

Front

What is the function of a receptor in cell communication?

Back

Receptors are proteins that bind to signaling molecules (ligands) and initiate a cellular response.